Induction heating is the process of heating an electrically conducting object (usually a metal) by electromagnetic induction, where eddy currents (also called Foucault currents) are generated within the metal and resistance leads to Joule heating of the metal. An induction heater includes an electromagnet through which a high-frequency alternating current (AC) is passed (i.e., an inductive coil coupled to a susceptor), to generate eddy currents in the metal (i.e., the susceptor). The frequency of AC used in induction heating depends on the object size, material type, coupling (between the work coil and the object to be heated) and the penetration depth. Heat may also be generated by magnetic hysteresis losses in materials that have significant relative permeability.
An exemplary prior art susceptor is shown in FIG. 1. As shown in FIG. 1, the prior art susceptors 100 are made of a single piece of material. A single coil is also typically provided and inductively coupled to the single-piece susceptor. The distance between the coil and susceptor can be varied. Current inductive heating systems, however, cannot heat substrates in a segmented pattern or with a single power source with varying heat patterns.